The total water available for diversion from the Mahaveli
basin in an average year is about 2,350 billion acre feet (2900 mcm) along with
700 mcm from medium-sized reservoirs in the system. Phase III, the
Originally, the Canal was to proceed north along the
island’s central ridge, first to discharge on
its left bank into Kapirigama Reservoir in Horawapotana, which connects with
Malwathu Oya (Aruvi Aru). Then a little further north on the right bank into
Yan River, and further on, east of Vavuniya, on the right bank into the
proposed Mukunu and Kitulgala Tanks, which connect with Padaviya and System L.
Finally, on reaching its northern extremity, it was to discharge into
The NCP canal was meant to provide water for Mahaveli Systems I (Aruvi or Malwathu River basin, Anuradhapura and Mannar Districts), J (Northwest Vanni), K (North Central Vanni, Kanagarayan Aru basin), L (Northeast Vanni – Padaviya North and Manal Aru), and M (North Trincomalee and NCP – Yan River basin). The Canal was in the Master Plan meant to develop 324,000 acres or 131,000 ha (Ratna S. Cooke, Accelerated Mahaveli Development Project, Institution of Engineers Sri Lanka, 1982). But the project developed in such a way that owing to strong preference by farmers, crops other than rice have been largely ruled out, making the annual water requirement of 2,440 mcm from the NCP Canal in the Initial Assessment Report (IAR) by far out of the question.
The current policy of extending settlements northward with far too little water, means that the original Sinhalese beneficiaries in System H of the NCP who face inbuilt shortages, have no recourse to rectify their scarcity. The original Master Plan gave low priority to Phase III and had doubts about its feasibility. “After meeting the irrigation demand in Phases I & II [which includes System H], the surplus water is recommended for diversion to the North Central parts of the island in Phase III” (Ratna Cooke, ibid).
To those who identified with the political agenda of the Mahaveli Project in the early 1980s and writhed under the humiliations it brought them, the end of the war in 2009 seemed too good an opportunity to miss. The agenda is based on Systems I, J, K and L of the Mahaveli Master Plan. By 2011, the Sri Lankan Army was quietly directed to ready the ground through land acquisitions. Some of the key milestones during 2012 are:
System I: The area west of Vavuniya was already targeted by JOSSOP (Joint Special Services Operations) as soon as it began operations in October 1983. It evicted Hill Country Tamil refugees settled on lands held on permit by Tamils (Appendix 9).
At the end of September 2012, Manik Farm was cleared of IDPs from the recent war. The Sunday Times (30 Sept. 2012) reported that top Sinhalese officials including the new GA Vavuniya, Harishchandra, met to decide on the disposal of 6,000 acres of lands directly below the Malwathu dam site at Kappachchi (see Appendix 9).
System J: The Uthayan daily
Among the uses of the military to spearhead changes is to turn independent or potentially independent farmers into wage labourers for private capital. In Thevamutty, Vellankulam, the permit holders had left or become refugees and the LTTE had cultivated a large measure of the land. After the war, the Agriculture Department was the first to clear the land intending to use local people to restore it, and in time making them owner-cultivators. On learning of this, a government order from high up forced the Agriculture Department to desist. Using the land powers the Governor exercises in lieu of the vacant provincial council, the President’s son Namal Rajapakse gave 100 acres of the land to the private company CIC, to open its Seed and Planting Material Production Farm. The people now work for the CIC as wage labourers as they had previously done for the LTTE. This area is downstream of the projected Pali Aru reservoir.
K: Four thousand acres of land have been taken over
in Murukandi and Kilinochchi to build a new military cantonment, dispossessing
inhabitants of three villages (Ranga Jayasuriya in Lakbimanews,
The lands mentioned above, confiscated from Tamils, lie downstream (north) of Kanagarayan Aru (River), where the System K dam has been planned. Similarly 900 acres have been ear-marked with housing for 450 soldier families at Akkarayan.
about 2007 until May 2012, the Rajapakse government was loquacious on reviving
the NCP Canal Project of the Mahaveli Scheme. The proposed Malwathu dam on
was clear is that the Government had made plans for large Sinhalese settlements
in the North and was determined to carry them through with or without water.
Months later, the Government Agent (GA), Anuradhapura, told a low level
briefing (Daily News 24 Jul.2013)
that the construction of the Malwathu Reservoir by the Irrigation and Water
Resources Management Ministry was to begin with plans for a settlement of 2100
ha just below the reservoir around Manik Farm (water requirement 63 mcm). The
GA gave the estimated cost of the construction as Rs. 7.5 billion for the 285
mcm reservoir as against the Rs.28 billion contract to the Chinese for the 169
mcm Yan Oya reservoir. Evidently even
The Aruvi’s annual river flow is 713 mcm of which 564 mcm or 79 percent of the total is used for irrigation. “Almost all the surface water potential in the four basins [of the NCP] (except Yan Oya) is [fully] utilized” (Sakthivadivel et al, ibid p.31). The 235 mcm mean annual flow at Kappachchi, becomes in two out of four years less than 159 mcm (the 50 percent dependable flow) and in one out of four, less than 84 mcm (the 75 percent dependable flow). The nature of the terrain is such that a marginal drop in rainfall leads to a sharp drop in river flow; the proportion of the reduction in river flow to reduction in rainfall, is far more drastic in the Malwathu-Aruvi Basin than for the Mahaveli Basin. Owing to the heavy fluctuations, the 50 percent dependable flow, rather than the mean flow, is the basis for planning (Table 2.8 on Surface Water Availability in FN.9). 
of the flow at Kappachchi, 84 mcm is diverted downstream at
in a year of 50% dependable flow in
Consequences of Malwathu Reservoir for farmers under Giant’s Tank: What the foregoing tells us is that if the flow to Giant’s and Akaththimurippu Tanks is not meddled with, only a 75 mcm is available in a year of 50% dependable flow and none whatsoever in a year of 75% dependable flow.
The World Bank Report ‘Major
Irrigation Rehabilitation Project’ of
WB 84 gave the cultivation intensity under Giant’s Tank as 88% (0.88) and placed 40 percent of the beneficiary population living below poverty level. Others in the low range of cultivation intensity were Morawewa 90% and Huruluwewa 100%. The rest were 120% and above. The greater contrast was in the per capita (annual) income per family member, which was Rs.400 p.a. for Giant’s Tank as against Rs.1830 in Iranamadu and Rs. 2060 for Rajangana, although the average land holdings were respectively 3.2 ha, 2.0 and 0.9. The last, Rajangana, had a cropping intensity of 1.63. All had average family sizes of 5.5, then compatible with Maritimepattu in Mullaitivu. The project sought to improve incomes through improving water supply and cropping intensity through the introduction of soya for alternative cropping during summer. The project was to last six years and owing to the constraint on water, envisaged the improvement in cropping intensity for Giant’s Tank only up to 95%, with 142.5% for Iranamadu (from 125%) and 150% and above for the rest.
For 25 years since that time, the people under Giant’s Tank suffered under both the Army and the LTTE, and particularly during the last phase of the war. The Muslims had been driven out by the LTTE in 1990. The consequences of the Malwathu dam would threaten the people’s tenuous existence. Notwithstanding promises of plenty of water and prosperity by the government, the people under Giant’s Tank, require an altogether new scheme as the principle of the present tekkam itself limits the flow p.a. to around 84 mcm.
WB 84 sought to improve the performance at Giant’s Tank System by: raising the full supply level of tank by one foot and re-modelling the tank feeder for 28.3 cubic metres/ sec (1,000 cubic feet/s) to divert to the tank part of the spill at Tekkam anicut (then about 40% of inflow). The envisaged returns for the whole project were:
Based on the hydrological studies, the assured cropping intensities with the project have been taken as: Kantalai, 150%; Huruluwewa, 150%; Nachchaduwa, 150%; Rajangana, 188%; Iranamadu, 143%; Giant’s, 95%; and Morawewa, 150%.
These were modest improvements possible within the existing framework. Alternative cropping with Soya during summer (yala), was not recommended for the Giant’s Tank System, owing to the low availability of water in summer. Postwar, government ministers and irrigation officials have promised the Giant’s Tank farmers round the year cultivation, while in reality the outcome would be to take away even the little they have.
Besides, similar promises were made to hard pressed Sinhalese farmers in Padaviya with cropping intensities well below 1.0. The source of water has been identified – namely Moragahakande – however it turns out that these farmers would only get water to top up their cropping intensities to 1.0, because the bulk of the water has been reserved for the ideological settlement of Weli Oya. What chance do forgotten Tamil farmers under Giant’s Tank have of any good coming from the Government’s promises?
Given the nature of politics of this country, once Malwathu Reservoir is built there would be pressure to maximise the impounding of water with or without an alternative source, and maximise Sinhalese settlement. As we pointed out earlier, diverting more Mahaveli water would mean a phenomenal rise in the cost of electricity and it is for this reason that even Sinhalese farmers in the NCP have been denied additional water for nearly 30 years.
The only justification one could find for the Malwathu
Reservoir is the estimated figure of
the absence of the NCP Canal the plan as presented by Minister de Silva (
The foregoing tells us that the average local flow into the intended Kanagarayan Tank is roughly is 25 mcm (as distinct from the 65 mcm envisaged in IAR, op. cit.). The average flow into Iranamadu Tank obtained by reducing the total runoff in proportion to the catchment areas concerned, using the river flows from Amerasinghe et. al., is 147 mcm without Kanagarayan Tank and 123 mcm with Kanagarayan Tank; the corresponding 50% dependable flows are 121 mcm and 102 mcm and the 75% dependable flows 80 mcm and 68 mcm. We can check that the average of 147 mcm corresponds closely with the cropping intensity of 95% for winter and 30% for summer given by WB 84 (total 125%). In this respect IFAD’s cropping intensity of 150% for 2011 is not representative. We will look at the two sets of recommendations:
WB 84 (November 1984): raising the full supply level by one foot to utilize part of the spill (about 30% of inflow), repairs to spillway damage (1984 floods), and providing inverted filter at dam toe in areas showing seepage;
(2010): Under the ADB, AFD and Government financed
Raising the bund by 1 foot (30 ft of water to 31 ft., water
spread = 5750 acres – S. Arumugam) makes room for an additional 7.1 mcm. But
the second plan envisages an additional 16.3 mcm of water out of which 9.85 mcm
is sent to
We seem to have modern planners who do not look at
past studies, fail to consult local expertise, and move ahead on their own
fantasies. Way back in 1971, the equivalent of Engineer in Society was introduced
as a subject in the
The foregoing suggests that advancing Sinhalisation in the name of rehabilitating the war-affected, risks creating conditions of famine during periods of prolonged low rainfall. We need to keep in mind that small perturbations of conditions in the dry zone lead to drastic changes in the environment. A safety factor appropriate to the dry zone has been totally disregarded in pressing ahead with settlements. An observed trend in the last several decades (not necessarily long term) is declining average rainfall. Deforestation and other activities in the watershed, such as construction and intensive cultivation, degrade the water in rivers and interfere with flows.
Initial Assessment Report – Updated
Mahaweli Water Resources Development Plan, SMEC International Pty Ltd. in
association with DHI Water and Environment (
 The following from IAR gives the land area identified for cultivation in hectares (ha) and the amount of water each system was to receive from the NCP Canal to supplement local water availability in mega cubic metres (mcm – 1 mcm = 810.7 acre feet) and the additional reservoir capacity needed: I – 914 mcm, 52 900 ha, two reservoirs 294 mcm; J – 377 mcm, 22 8000 ha, two reservoirs 504 mcm; K – 166 mcm, 8100 ha, one reservoir 124 mcm; L – 985 mcm, 39 000 ha, two reservoirs 291 mcm; M – 106 mcm, 11 300 ha, one reservoir 235 mcm.
 UTHR Report No.11: “From that time Tamils
became subject to small scale attacks by air force men and Sinhalese hooligans.
The largest number of killings of Tamils took place along the
to the report, apart from Tamil families (some of whom had fled to
 Amaithipuram (7 mi north of Old Murikandi in the Thunukkai DS Division): 200 acres for the Commando Regiment. Kottaikattiyakulam (8 mi West of Old Murikandi): 150 acres on demand. Thenniankulam (7 mi NNW of Thunukkai): 46 acres for the armed services. Old Murikandy: 80 acres for the armed services. Therankandal (3 mi NNE of Thunukkai): 250 acres for the 53rd Division and 50 acres for the armed services. Alankulam (1 ½ mi NNE of Thunukkai): 112 acres on demand
 Irrigation Secretary Ivan de Silva, quoted in Daily News
 In 1961 the Soviet (now Russian) consultants Technopromexports prepared a project for Malwathu Reservoir with storage capacity 347 mcm (Arumugam), but other details such as sources of water are not easily accessible. Under the NCP Canal Project in the 1969 Master Plan there were to be two reservoirs Malwathu Reservoir with 275 mcm and Kapirigama upstream, near the Canal discharge, with 91 mcm.
Among these tanks are Nachchaduwa, Mahakandarawa, Nuwarawewa, Iratperiyakulam, Pavatkulam, Akattimurippukulam, and finally Giant’s Tank, 32,000 ac. ft. or 40 mcm). According to IAR about 360 mcm is already used to irrigate 12,270 ha under medium-sized tanks and 8,830 ha under small tanks.
 R. Sakthivadivel, C.R. Panabokke, C.M. Wijeratna, Nihal Fernando, K. Jinapala, R.B. Bandula Sirimal; Pre-Project Technical Assistance Study for Proposed Area Development Project of North Central Province, Prepared for RH&H Consultant/ ADB, 1995
 The river basin area for
 101.6 mcm, from the Polgolla Diversion of 875 mcm, flows into
Malwathu-Aruvi Subsystem (Table 2.5 & Plate 4 of Sakthivadivel et al,
F.N.8). This water is used to support cultivation under Nachchaduwa, Nuwara
Wewa and Tissa
Wewa Tanks coming under System H, but has not added to cultivation in the
 Considering the mean, 50% and 75% dependable rainfall variations in
“The strategy for water resources development should be to maximise productivity per unit of water in the Malwathu-Aruvi basin and to maximize productivity per unit of land in the Polonnaruwa District” – FN.8.
 13.3 mcm, local flow from the 38 sq. mi. of catchment area (Arumugam) assuming 15% runoff compatible with Table 2.2 of Manchanayake and Bandara (op. cit.).
 Water Statistics Handbook,
 Grumusols (clay loan to clay) are characterized by low permeability and high available water and are very suitable for rice cultivation but need puddling for land preparation (WB 84 op. cit.).
 Alluvial soils (sandy clay loam to sandy clays) have higher infiltration rates and less available water. However, these soils are also being used entirely for paddy cultivation. Iranamadu soils are alluvial (deep sandy, shallow to moderately deep sandy) and clayey. The alluvial soils occur at higher levels. These permit tillage under dry conditions, can be maintained under saturated conditions because of clays below, and are therefore used extensively for rice in Maha. The clayey soils occur in valleys. (WB 84)
 The International Fund for Agricultural Development, Iranamadu Irrigation Development Project, October 2011: http://www.ifad.org/operations/projects/design/104/srilanka.pdf
 The average rainfall (1265 mm), river ruoff (19.1%) and catchment
area (907 sq. km.) for
 Water Scarcity Variations within a Country: A Case Study of
 We ignore the 25.6 mcm the 5750 acres of the tank spread receives from an average rainfall of 43.3 in p.a. since this is less than the average evaporation of 56.5 in
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